Inhalers are used to provide chronic portable delivery of medicaments to treat certain conditions. One well-known type of inhaler is used to treat respiratory conditions such as asthma.
Dry powder inhalers (DPI's) represent a promising alternative to pressurized pMDI (pressurized meted dose inhaler) devices for delivering drug aerosols without using CFC propellants. See generally, Crowder et al., 2001: an Odyssey in Inhaler Formulation and Design, Pharmaceutical Technology, pp. 99-113, July 2001; and Peart et al., New Developments in Dry Powder Inhaler Technology, American Pharmaceutical Review, Vol. 4, n. 3, pp. 37-45 (2001). Typically, the DPIs are configured to deliver a powdered drug or drug mixture that includes an excipient and/or other ingredients.
In operation, DPI devices strive to administer a uniform aerosol dispersion amount in a desired physical form (such as a particulate size) of the dry powder into a patient's airway and direct it to a desired deposit site(s). If the patient is unable to provide sufficient respiratory effort, the extent of drug penetration, especially to the lower portion of the airway, may be impeded. This may result in premature deposit of the powder in the patient's mouth or throat.
Some inhalation devices have attempted to resolve problems attendant with conventional passive inhalers. For example, U.S. Pat. No. 5,655,523 proposes a dry powder inhalation device which has a deagglomeration/aerosolization plunger rod or biased hammer and solenoid, and U.S. Pat. No. 3,948,264 proposes the use of a battery-powered solenoid buzzer to vibrate the capsule to effectuate the release of the powder contained therein. These devices propose to facilitate the release of the dry powder by the use of energy input independent of patient respiratory effort. U.S. Pat. No. 6,029,663 to Eisele et al. proposes a dry powder inhaler delivery system with a rotatable carrier disk having a blister shell sealed by a shear layer that uses an actuator that tears away the shear layer to release the powder drug contents. The device also proposes a hanging mouthpiece cover that is attached to a bottom portion of the inhaler. U.S. Pat. No. 5,533,502 to Piper proposes a powder inhaler using patient inspiratory efforts for generating a respirable aerosol and also includes a rotatable cartridge holding the depressed wells or blisters defining the medicament holding receptacles. A spring-loaded carriage compresses the blister against conduits with sharp edges that puncture the blister to release the medication that is then entrained in air drawn in from the air inlet conduit so that aerosolized medication is emitted from the aerosol outlet conduit. The contents of these patents are hereby incorporated by reference as if stated in full herein.
More recently, Hickey et al., in U.S. patent application Ser. Nos. 10/434,009 and 10/204,609, has proposed a DPI system to actively facilitate the dispersion and release of dry powder drug formulations during inhalation using piezoelectric polymer film elements which may promote or increase the quantity of fine and/or respirable particles dispersed or emitted from the device over conventional DPI systems. The contents of these documents are hereby incorporated by reference as if recited in full herein.
Notwithstanding the above, there remains a need for easily used, cost effective, and/or reliable inhalers.